Assessing the Vulnerability of Ramsar Wetlands Through an Ecological Character-Based Framework: A Case Study of Bau Sau, Vietnam

Wetland vulnerability assessment is essential for identifying interacting pressures, detecting potential changes in ecological character, and supporting adaptive management of Ramsar Sites. This study develops an ecological character-based vulnerability assessment framework and applies it to the Ramsar Site Bau Sau (Crocodile Lake, Ramsar Site No. 1498) in Cat Tien National Park, Vietnam. The framework integrates 26 indicators within six criterion groups and three components: exposure/pressure (E), sensitivity (S), and adaptive capacity/resilience (AC). Indicators were selected to explicitly link climatic, hydrological, ecological, and anthropogenic pressures with the ecosystem components, processes, and functions that define wetland ecological character. The assessment yielded E = 0.500, S = 0.604, and AC = 0.688, resulting in an overall vulnerability index of V = 0.472, classified as moderate. Hydrological variability, inundation dynamics, and hydrological-environmental sensitivity emerged as the principal drivers of vulnerability, whereas relatively strong conservation, management, and monitoring capacity reduced overall vulnerability. The findings indicate that maintaining hydrological processes and ecological character should be central to adaptive management at Bau Sau. More broadly, the proposed framework provides a transparent and adaptable approach for linking Ramsar ecological-character principles with quantitative vulnerability assessment and management prioritization in data-limited wetlands.